Comments only: extend "Implementation note about image drawing" to describe the mask_bitmap virtual member function.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12845 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 2 insertions, 0 deletions

diff --git a/FL/Fl_Graphics_Driver.H b/FL/Fl_Graphics_Driver.H
index 5fb18f75f..c7ba46f15 100644
--- a/FL/Fl_Graphics_Driver.H
+++ b/FL/Fl_Graphics_Driver.H
@@ -130,6 +130,8 @@ and
    Graphics drivers also implement cache(Fl_Pixmap*), cache(Fl_Bitmap*) and cache(Fl_RGB_Image*)
    to compute the cached form of all image types, and uncache(Fl_RGB_Image *,...),
    uncache_pixmap(fl_uintptr_t) and delete_bitmask(Fl_Bitmask) to destroy cached image forms.
+   Graphics drivers that use the mask_ variable of class Fl_Pixmap to cache an Fl_Pixmap
+   object also reimplement the uchar **Fl_Graphics_Driver::mask_bitmap() member function.
    */
 private:
   virtual void draw_fixed(Fl_Pixmap *pxm,int XP, int YP, int WP, int HP, int cx, int cy) {}